System and method for correcting scoliosis

ABSTRACT

A wedge has an outer perimeter and includes a top surface extending generally in a first plane and having a top osteointegration surface disposed thereon. A bottom surface extends in a second plane that extends obliquely with respect to the first plane. The first plane intersects the second plane outside the outer perimeter of the implant and includes a bottom osteointegration surface disposed thereon. A plurality of side surfaces extends between the top surface and the bottom surface and defines the outer perimeter, wherein at least a portion of the plurality of side surfaces is devoid of any osteointegration surface.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation of co-pending application Ser. No. 15/162,657,filed May 24, 2016, which is a continuation-in-part of co-pendingapplication Ser. No. 14/948,322, filed on Nov. 22, 2015, which is acontinuation-in-part of co-pending application Ser. No. 14/513,300,filed on Oct. 14, 2014, which is a Continuation-in-Part application ofU.S. patent application Ser. No. 14/054,100, filed on Oct. 15, 2013,which claims priority from U.S. Provisional Patent Application Ser. No.61/715,891, filed on Oct. 19, 2012, all of which are incorporated byreference herein in their entireties.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to surface treatments on medical implantdevices, surgical tools, and other devices that are designed to inhibitmicrobial adhesion and/or growth and to promote osteointegration.

Description of the Related Art

In the pathogenesis of infection around implants, the initial adhesionof bacteria onto biomaterial surfaces is a critical first step. Animportant strategy in the reduction of orthopedic infections is todevelop implant materials that prevent initial bacteria adhesion andsubsequent growth onto implant surfaces. Bacterial localization andbiofilm formation may lead to acute and chronic infections. Biofilmformation on implant surfaces protects bacteria from the immune systemand antibiotic therapy, thus requiring an aggressive treatment ofantibiotics that frequently do not work post biofilm formation.Therefore, to reduce or even prevent implant infections, variousstrategies have been developed aside from conventional systemic andlocal antibiotic treatment. Recently, there has been increasing interestfor coating implants with other materials to improve osteointegrationand prevent infection, chronic inflammation, and unwanted foreign bodyresponses.

It would be beneficial to provide a surface treatment on medicalimplants and other medical devices that inhibit microbial adhesion andgrowth and enhance osteointegration of the implant into existing tissue.

SUMMARY OF THE INVENTION

This Summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used to limit the scope of the claimed subject matter.

In one embodiment, the present invention is a medical device comprisinga substrate having an exposed surface and a texture over at least partof the exposed surface. The texture comprises a plurality ofnanofeatures that inhibit bacterial adhesion on the surface.

In another embodiment, the present invention is a medical devicecomprising a substrate having an exposed surface and a texture over atleast part of the exposed surface. The texture comprises a plurality ofnanofeatures that inhibit bacterial growth on the surface and have asize range between about 0.01 nanometers and about 1,000 nanometers.

In still another embodiment, the present invention is a medical devicecomprising a substrate having an exposed surface and a texture over atleast part of the exposed surface. The texture comprises a plurality ofnanofeatures applied thereto. The texture has a first particle size at afirst location, a second particle size at a second location, and agradient of particle size from the first particle size to the secondparticle size between the first location and the second location.

BRIEF DESCRIPTION OF THE DRAWINGS

Other aspects, features, and advantages of the present invention willbecome more fully apparent from the following detailed description, theappended claims, and the accompanying drawings in which like referencenumerals identify similar or identical elements.

FIG. 1 shows a perspective view of a wedge implant according to a firstexemplary embodiment of the present invention;

FIG. 2 shows a lateral side elevational view of the wedge implant shownin FIG. 1;

FIG. 3 shows a posterior side elevational view of the wedge implantshown in FIG. 1;

FIG. 4 shows a lateral side elevational view of the wedge implant shownin FIG. 1 inserted into a vertebra in a spinal column;

FIG. 5 shows a posterior side elevational view of the wedge implantshown in FIG. 1 inserted into a vertebra a spinal column;

FIG. 6 shows a retaining plate used to retain the wedge implant shown inFIG. 1 in the vertebrae shown in FIGS. 4 and 5;

FIG. 6A shows a lateral side elevational view of the wedge implant shownin FIG. 1 inserted between adjacent vertebrae in a spinal column;

FIG. 7 shows an enlarged view of an osteointegration surface used tocoat a portion of the wedge implant shown in FIG. 1;

FIG. 8 shows a perspective view of a wedge implant assembly according toa second exemplary embodiment of the present invention;

FIG. 9 shows a lateral elevational view of the wedge implant assemblyshown in FIG. 8;

FIG. 10 shows a posterior elevational view of the wedge implant assemblyshown in FIG. 8;

FIG. 11 shows a perspective view of a wedge implant assembly accordingto a third exemplary embodiment of the present invention;

FIG. 12 shows a posterior elevational view of the wedge implant assemblyshown in FIG. 11;

FIG. 13 shows a perspective view of a wedge implant assembly accordingto a fourth exemplary embodiment of the present invention;

FIG. 14 shows a medial side elevational view of the wedge implantassembly shown in FIG. 13;

FIG. 15 shows a rear perspective view of the wedge implant assemblyshown in FIG. 13;

FIG. 16 shows a lateral side elevational view of the wedge implantassembly shown in FIG. 15;

FIG. 17 shows a rear perspective view of the wedge implant assemblyshown in FIG. 15, with a second wedge assembly actuated to adjust thetilt angle of the top surface of the wedge implant assembly;

FIG. 18 shows a perspective view of a wedge implant assembly accordingto a fifth exemplary embodiment of the present invention;

FIG. 19 shows a right side elevational view of the wedge implantassembly shown in FIG. 18 inserted into a vertebra of a patient;

FIG. 20 shows a posterior side elevational view of the wedge implantassembly and vertebra shown in FIG. 19;

FIG. 21 shows a left side elevational view of the wedge implantassembly, and vertebra shown in FIG. 19;

FIG. 22 shows a posterior side elevational view of the wedge implantassembly shown in FIG. 18, inserted between two adjacent vertebrae;

FIG. 23A shows an untreated titanium surface and bacterial growththereon;

FIG. 23B shows the surface of FIG. 23A treated with TiO₂ after 16 hoursof incubation;

FIG. 23C shows a Scanning Electron Microscope (SEM) image of theuntreated titanium surface;

FIG. 23D shows an SEM image of the treated TiO₂ surface after 16 hoursof incubation;

FIG. 24 shows a side elevational view of a treated substrate accordingto an exemplary embodiment of the present invention;

FIG. 25 shows a side elevational view of a treated substrate accordingto another exemplary embodiment of the present invention;

FIG. 26 shows a side elevational view of a treated substrate accordingto still another exemplary embodiment of the present invention;

FIG. 27 shows a side elevational view of a treated substrate accordingto another exemplary embodiment of the present invention;

FIG. 28 shows a side elevational view of a treated substrate accordingto yet another exemplary embodiment of the present invention;

FIG. 29 shows a graph of different sized nanofeatures and their effecton S. aureus bacteria on a substrate; and

FIG. 30 shows a graph of the different sized nanofeatures and theireffect on osteointegration capability on substrate.

DETAILED DESCRIPTION

In the drawings, like numerals indicate like elements throughout.Certain terminology is used herein for convenience only and is not to betaken as a limitation on the present invention. For purposes of thisdescription, the terms “anterior”, “posterior”, “lateral”, “medial”,“superior” and “inferior” describe the position of surfaces or featuresrelative to the anatomy. The term “anterior” refers to features having arelative position toward the front side of a spine, and “posterior”refers to features having a relative position toward the rear side ofthe spine. The term “lateral” refers to features having a relativeposition toward the left or right side of the spine. The term “medial”refers to features having a relative position toward the center of thespine. The term “cranial” refers to features having a relative positionabove other features, and the term “caudal” refers to features having arelative position below other features. The terminology includes thewords specifically mentioned, derivatives thereof and words of similarimport.

The embodiments illustrated below are not intended to be exhaustive orto limit the invention to the precise form disclosed. These embodimentsare chosen and described to best explain the principle of the inventionand its application and practical use and to enable others skilled inthe art to best utilize the invention.

Reference herein to “one embodiment” or “an embodiment” means that aparticular feature, structure, or characteristic described in connectionwith the embodiment can be included in at least one embodiment of theinvention. The appearances of the phrase “in one embodiment” in variousplaces in the specification are not necessarily all referring to thesame embodiment, nor are separate or alternative embodiments necessarilymutually exclusive of other embodiments. The same applies to the term“implementation.”

As used in this application, the word “exemplary” is used herein to meanserving as an example, instance, or illustration. Any aspect or designdescribed herein as “exemplary” is not necessarily to be construed aspreferred or advantageous over other aspects or designs. Rather, use ofthe word exemplary is intended to present concepts in a concretefashion.

Additionally, the term “or” is intended to mean an inclusive “or” ratherthan an exclusive “or”. That is, unless specified otherwise, or clearfrom context, “X employs A or B” is intended to mean any of the naturalinclusive permutations. That is, if X employs A; X employs B; or Xemploys both A and B, then “X employs A or B” is satisfied under any ofthe foregoing instances. In addition, the articles “a” and “an” as usedin this application and the appended claims should generally beconstrued to mean “one or more” unless specified otherwise or clear fromcontext to be directed to a singular form.

Referring to FIGS. 1-6, a wedge implant 100 according to a firstexemplary embodiment of the present invention is shown. Wedge implant100 is inserted into a single vertebra 50 in a spine 52 to readjust thecaudal and cranial plans of vertebra 50 to alleviate scoliosis in spine52. While a single wedge implant 100 is shown being inserted into asingle vertebra 50, those skilled in the art will recognize thatadditional wedge implants 100 can also be inserted into additionalvertebrae 50 as needed to alleviate scoliosis.

Wedge implant 100 includes an outer perimeter 102 that defines implant100. Wedge implant 100 also includes a top surface 104 extendinggenerally in a first plane P1 and a bottom surface 106 extending in asecond plane P2. Second plane P2 extends obliquely with respect to firstplane P1. As shown in FIG. 2, first plane P1 intersects second plane P2at a location “I” outside outer perimeter 102 of implant 100. Topsurface 104 and bottom surface 106 can be planar surfaces.Alternatively, top surface 104 and bottom surface 106 can have othershapes, such as, for example, domed surfaces.

A medial surface 110 extends between top surface 104 and bottom surface106 proximate to the intersection of first plane P1 and second plane P2.A lateral surface 112 extends between top surface 104 and bottom surface106 distal from the intersection of first plane P1 and second plane P2.An anterior surface 114 extends a first distance D1 between top surface102 and bottom surface 104 between medial surface 110 and lateralsurface 112. Anterior surface 114 extends generally a constant firstdistance D1 across its length. A posterior surface 116 extends a seconddistance D2 between top surface 104 and bottom surface 106 betweenmedial surface 110 and lateral surface 112. Posterior surface 116extends generally a constant second distance D2 across its length.Second distance D2 is greater than first distance D1.

In an exemplary embodiment, body 102 is constructed from a materialhaving a relatively low stiffness, such as, for example,poly-ether-ether ketone (“PEEK”), which has a modulus of elasticityabout 3.6 GPa. In an exemplary embodiment, an antimicrobial and/orosteointegration surface 120, shown in detail in FIG. 7, can be disposedon each of top surface 104 and bottom surface 106. In an exemplaryembodiment, the osteointegration portion of surface 120 can be titaniumand the antimicrobial portion of surface 120 can be silver or titaniumnanotextured or titanium oxide nanostructured.

Osteointegration surface 120 extends downwardly from top surface 104along medial surface 110, lateral surface 112, anterior surface 114, andposterior surface 116 only a portion of the way to bottom surface 106.Similarly, osteointegration surface 120 can extend upwardly from bottomsurface 106 along medial surface 110, lateral surface 112, anteriorsurface 114, and posterior surface 116 only a portion of the way to topsurface 104, resulting in a band 122 around outer perimeter 102 ofimplant 100 that is free from osteointegration surface 120. In anexemplary embodiment, band 122 has a cranial-to-caudal dimension ofabout 0.01 mm. Alternatively, band 122 can have a cranial-to-caudaldimension of greater than about 0.1 mm. The existence of band 122 allowsfor flexing of implant 100, which is softer with a lower modulus ofelasticity than osteointegration surface 120, without loadingcompressive forces onto osteointegration surface 120.

To correct adult or pediatric scoliosis deformity, implant 100 can beinserted into vertebra 50 in a lateral-to-medial direction to realignspine 52 with the craniocaudal axis 59, as shown in FIG. 5. To insertwedge 100, an osteotomy is performed on vertebra 50 by making anincision 56 in vertebra 50. In an exemplary embodiment, the insertion 56can be made from lateral side 58 of vertebra 50 inwardly toward thecenter of vertebra 50, and inserting implant 100 into incision 56.Alternatively, incision 56 may be made to the contralateral side ofvertebra 50, with implant 100 being inserted therein. In pediatricpatients, the osteotomy is formed in a way not violate the growth plateof vertebra 50. This insertion effectively pivots cranial plane P3relative to caudal plane P4 of vertebra 50 in an effort to make cranialplane P3 and caudal plane P4 closer to match the crainocaudal axis ofspine 52 and aligned in the sagittal plane.

Similarly, to correct adult or pediatric scoliosis deformity, implant100 can be inserted into vertebra 50 in a anterior-to-posteriordirection to restore lordosis or kyphosis of the spine, as shown in FIG.4. To insert wedge 100, an osteotomy is performed on vertebra 50 bymaking an incision 64 in vertebra 50 from posterior side 65 of vertebra50 inwardly toward anterior side 66 of vertebra 50, and insertingimplant 100 into incision 64. This insertion effectively pivots cranialplane P3 relative to caudal plane P4 in an effort to make cranial planeP3 and caudal plane P4 closer to normal conditions to restore lordoticor kyphotic angulation the spine 52.

In either of the above two procedures, a retaining plate 180 is fixed tovertebra 50 to secure implant 100 to vertebra 50. FIG. 6 shows retainingplate 180 being used to secure implant 100 inserted in theposterior-to-anterior direction in top vertebra 50, and retaining plate180 used to secure implant 100 inserted in the lateral-to-medialdirection. The retaining plate 180 is shown in both anterior-posteriorand medial-lateral alignment. However a surgeon will generally onlyinsert retaining plate 180 from one direction in vertebra 50 or adjacentvertebrae 50.

Retaining plate 180 is an elongate member with a first hole 182 at afirst end 184 thereof and a second hole 186 at a second end 188 thereof.A first screw 190 is inserted through first hole 182 and into vertebra50 toward or parallel with cranial plane P3, while a second screw 192 isinserted through second hole 186 and into vertebra 50 toward parallelwith caudal plane P4. In an exemplary embodiment, retaining plate 180and screws 190, 192 can be made from standard biomaterials, such astitanium, or bio-resorbable materials, such as, for example,magnesium-based alloys that will ultimately dissolve by the time implant100 has been fully engaged by vertebra 50.

While an exemplary use of implant 100 as described above is used in asingle vertebra 50, those skilled in the art will recognize that in somecases, it may be more advantageous to remove a disk 70 between twoadjacent vertebrae 50 and insert implant 100 between the two adjacentvertebrae 50, as an interbody implant, as shown in FIG. 6A. In such acase, screw 190 for plate 180 can be secured into the upper vertebra 50and screw 192 for plate 180 can be secured into the lower vertebra 50.

In an exemplary embodiment, it may be necessary to remove at least alower portion of the upper vertebra 50 and an upper portion of the lowervertebra 50 in order to properly insert implant 100.

In an alternative embodiment, referring to FIGS. 8-10, a bi-planaradjustable implant 200 according to an exemplary embodiment of thepresent invention is shown. Implant 200 can be inserted into anosteotomy in vertebra 50 as discussed above with respect to implant 100.Alternatively, as also discussed above with respect to implant 100, uponremoval of a disk between two adjacent vertebrae 50, implant 200 can beinserted into the space between the two vertebrae 50.

Implant 200 includes a body 202 having a top surface 204 and a bottomsurface 206, distal from top surface 204. Top surface 204 and bottomsurface 206 can be planar surfaces. Alternatively, top surface 204 andbottom surface 206 can have other shapes, such as, for example, domedsurfaces.

A medial side 214 connects top surface 204 and bottom surface 206. Alateral side 220 is located distal from medial side 214. An anteriorside 210 extends between medial side 214 and lateral side 220 such thatanterior side 210 connects top surface 204 and bottom surface 206 toeach other. A posterior side 212 extends between lateral side 220 andmedial side 214, distal from anterior side 210.

Implant 200 has a first slot 230 extending from lateral side 220 towardmedial side 214 and a second slot 236 extending from posterior side 220toward anterior side 214. Slots 230, 236 allow for the insertion ofwedges to alter the angle of the plane of top surface 204 with respectto bottom surface 206. The location of slot 230 relative to slot 236allows for the adjustment of top surface 204 relative to bottom surface206 about two axes, namely, the x and z axes as shown in FIG. 8.

A first wedge assembly 240 is inserted into first slot 230. As usedherein, the term “wedge assembly” means any device, inserted in animplant, that can be manipulated to change the angle of at least oneface of the implant. First wedge assembly 240 has a first member 242translatable in a lateral-to-medial direction. In an exemplaryembodiment, first member 242 is a wedge having a tapered profile fromthe lateral direction to the medial direction as shown in FIG. 9. Asecond member 244 is operatively connected to first member 242 such thatoperation of second member 244 translates first member 240 in thelateral-to-medial direction. In an exemplary embodiment, second member244 can be a screw threadedly inserted through first member 242, suchthat rotation of second member 244 about the “Z” axis translates firstmember 242 in the “Z” direction. Second member 244 can include anadjusting mechanism 246, such as, for example, a screw head, extendingfrom anterior side 214.

Similarly, a second wedge assembly 250 is inserted into second slot 236.Second wedge assembly 250 has a first member 252 translatable in aposterior-to-anterior direction. Similar to first wedge assembly 240,first member 252 is a wedge having a tapered profile from the lateraldirection to the medial direction as shown in FIG. 10. A second member254 is operatively connected to first member 252 such that operation ofsecond member 254 translates first member 250 in theposterior-to-anterior direction. In an exemplary embodiment, secondmember 254 can also be a screw threadedly inserted through first member252, such that rotation of second member 254 about the “X” axistranslates second member 252 in the “X” direction. Second member 254 caninclude an adjusting mechanism 256, such as, for example, a screw head,extending from anterior side 210.

Translation of first member 242 of first wedge assembly 240 pivots topsurface 204 with respect to bottom surface 206 about medial side 214 andtranslation of first member 252 of second wedge assembly 250 pivots topsurface 204 with respect to bottom surface 206 about anterior side 210.

In an alternative exemplary embodiment of a wedge assembly 300, shown inFIGS. 11 and 12, instead of the wedge provided as first member 242 and252, wedge assemblies 340, 350 utilize a cylinder 342, 352. Secondmember 244, 254 from wedge assembly 200 can be used to activate cylinder342, 352, respectively. It is noted, however, that, for either wedgeassembly 200 or wedge assembly 300, first wedge assembly 240 is actuatedfrom lateral side 220 while second wedge assembly 250 is actuated fromposterior side 212. It is desired to be able to actuate both first wedgeassembly 240 and second wedge assembly 250 from the same side in orderto minimize incisions made into the patient. Therefore, if wedgeassembly 200, 300 is inserted from the lateral side of vertebra 50, itis desired to be able to actuate first wedge assembly 240 and secondwedge assembly 250 from the lateral side of vertebra 50. Therefore, toactuate second wedge assembly, it may be desired to use a driver (notshown) having a right angle drive.

An alternative embodiment of an implant assembly 400 according to thepresent invention is shown in FIGS. 13-17. Implant assembly 400 issimilar to implant assembly 300, with the exception of, instead ofsecond wedge assembly 350, a second wedge assembly 450 is provided.Second wedge assembly 450 includes a first member 452, which is acylinder having a plurality of gear teeth 454 formed around an exteriorperimeter thereof. Second wedge assembly 450 includes a second memberfixedly 456 connected to body 402 of implant assembly 400. In anexemplary embodiment, second member 456 is a toothed rack engageablewith gear teeth 454 of first member 452 such that, when first member 452is rotated, gear teeth 454 translates first member 452 along secondmember 456. An exemplary embodiment, as shown FIG. 17, two sets of gearteeth 454 are formed on first member 452 and two sets of toothed racksof second member 456 are connected to body 402, although those skilledin the art will recognize that more or less than two sets can be used.

An advantage of implant assembly 400 is that first member 342. A firstwedge assembly 340, and first member 452 of second wedge assembly 450can both be actuated from the same side of the patient, such as, forexample, the lateral side.

Translation of first member 342 of first wedge assembly 340 pivots topsurface 404 with respect to bottom surface 406 about medial side 414 andtranslation of first member 252 of second wedge assembly 250 pivots topsurface 204 with respect to bottom surface 206 about anterior side 410.

Also, similar to wedge implant 100, wedge implant assembly 200, 300, 400can include an antimicrobial and/or osteointegration surface disposed ontop and bottom surfaces thereof, with only a portion of each of themedial side, the lateral side, the anterior side, and the posteriorside, including the osteointegration surface disposed thereon. Analternative embodiment of an implant assembly 500 according to thepresent invention is shown in FIGS. 18-22. Implant assembly 500 is anon-adjustable wedge tapering in both the medial-lateral direction aswell as the posterior-anterior direction. Wedge 500 is similar to wedge100, but, instead of anterior surface 114 extending generally a constantfirst distance D1 across its length and posterior surface 116 extendinggenerally a constant second distance D2 across its length, as shown inFIG. 18, at least two adjacent surfaces taper from larger to smaller inboth the medial-lateral direction as well as the posterior-anteriordirection, forming a top surface 502.

By way of example only, anterior surface 510 tapers from larger tosmaller in a left-to-right direction (as viewed by the patient havingthe spinal column in FIG. 20) and lateral surface 512 tapers from largerto smaller in anterior-to-posterior direction, resulting in wedgeassembly 500 that can be implanted into vertebra 50, as shown in FIGS.19-22. An advantage of wedge assembly 500 is that wedge assembly 500 canbe used to simultaneously correct a spinal column 52 that has abnormalcurvature into the lateral-to-medial direction as well as in theposterior-to-anterior direction. Optionally, although not shown, aretaining plate 180 can be used to secure wedge assembly 500 in vertebra50.

FIG. 22 shows wedge assembly 500 inserted between two adjacent vertebrae50 with a disk, similar to disc 70 previously disposed between theadjacent vertebrae 50, having been removed and wedge assembly 500inserted therein. Optionally, plate 180 can be used to secure wedgeassembly 500 between the adjacent vertebrae 50 using screw 190 tosecured plate 180 to the upper vertebra 50 and screw 192 to secure plate180 to the lower vertebra 50. As shown FIG. 22, plate 180 is attached toa lateral side of spine 52. Those skilled in the art, however, willrecognize that plate 180 can also be attached to spine 152 along theposterior side of spine 52.

As used herein, the term “medical device” means a medical implant, aninsertion or other type of tool, or any other item that contacts or isinserted into a patient, including, but not limited to, the devices andstructures described above.

The medical device can be treated with a surface treatment that performsand/or achieves one or more of the following purposes: inhibition ofmicrobial, bacterial, and other types of unwanted adhesion on thesurface; inhibition of microbial, bacterial, and other types of unwantedgrowth on the surface; and enhanced osteointegration with bone and othertypes of living matter. Osteointegration can be defined as a “directstructural and functional connection between ordered living material,such as bone, and the surface of a load-carrying or other type ofimplant.”

FIGS. 23A-D are confocal images showing S. aureus colony forming unitson (a) untreated Ti and (b) treated TiO₂ after 16 hours of incubation.SEM images show the (c) untreated Ti surface and the (d) treated TiO₂surface. While TiO₂ was used to show the effectiveness of a treatedsurface with respect to bacteria, such as S. aureus, those skilled inthe art will recognize that other bacteria, microbes, and other unwantedgrowths can be inhibited and even killed using other nanofeatures suchas non-TiO₂ or non-oxides on an exposed surface. Examples ofnon-titanium base oxides can be AgO₂, while examples of non-oxides canby hydroxyapatite (HA) or CaPO₄. As used herein, the term “nanofeatures”is used to mean nanoparticles, nanotexturing, or other application to ormodification of a surface that results in nano-sized features orirregularities being present on the surface.

Referring to FIG. 24, a medical device 2400 includes a substrate 2402having an exposed surface 2404. Substrate 2402 can be constructed from ametallic material such as, for example, titanium or some otherbiocompatible material. Alternatively, substrate 2402 can be constructedfrom a non-metallic material such as, for example, polyether etherketone (PEEK) or some other biocompatible material. Still alternatively,substrate 2402 can be constructed from a mix/combination of metallic andnon-metallic materials.

A texture 2406 is formed over at least part of exposed surface 2404.Texture 2406 comprises a plurality of nanofeatures 2408 that can inhibitbacterial adhesion and/or growth on surface 2404. Additionally,nanofeatures 2408 can promote osteointegration with adjoining tissue 60.

In an exemplary embodiment, nanofeatures 2408 have a size range betweenabout 0.1 nanometers and about 1,000 nanometers. In another exemplaryembodiment, nanofeatures 2408 have a size range between about 20nanometers and about 50 nanometers and in yet another exemplaryembodiment, nanofeatures 2408 have a size range between about 0.1nanometers and about 10 nanometers.

In an exemplary embodiment, texture 2406 comprises an oxide, such as,for example, a titanium oxide or a titanium dioxide, although thoseskilled in the art will recognize that other types of oxides or evennon-oxides can be provided as texture 2406.

In a further exemplary embodiment, texture 2406 comprises the depositionof a coating of an oxide (or other nanofeatured material) onto substrate2402. In an exemplary embodiment of a deposition method, nanophasetitanium dioxide was synthesized using a wet chemical synthesis and wasdeposited on Ti-6Al-4V titanium screws (equivalent to substrate 2402)using a cathodic arc deposition plasma system. Bacterial assays wereconducted using Staphylococcus aureus (ATCC® 29740™), Pseudomonasaeruginosa (ATCC® 39324™) and an ampicillin resistant strain of E. coli(BIO-RAD Strain HB101 K-12 #166-0408 and pGLO Plasmid #166-0405). 0.03%tryptic soy broth (TSB) (Sigma Aldrich, Cat #22092) and agar(Sigma-Aldrich, Cat #A1296) were used as the media and colony formingassays were performed to determine bacterial adhesion.

Nanophase titanium dioxide was successfully synthesized and applied ontothe desired exposed surface of a substrate. A statistically significantdecrease in bacterial adhesion was observed across all 3 strains ofbacteria; an example of confocal images for S. Aureus is given in FIGS.23A-D. In addition, decreased macrophage functions and increaseosteoblast functions were also observed in the nano TiO₂ treated Ti6Al4Vscrews. It is noted that this was all achieved without the use of drugsand/or antibiotics, decreasing the chance for the spread of antibioticresistant bacteria and drug side effects.

An alternative method or nanotexturing surface 2404 is by surfaceetching or otherwise treating surface 2404 according to known methods.For example, a titanium surface can be bombarded with oxygen tosimultaneously texturize and oxidize surface 2404 such that thenanofeatures are formed from substrate 2402 itself.

Referring to FIG. 25, nanoparticles having a first particle size range2502 and a second particle size range 2504 can by mixed together andrandomly applied to substrate 2402. Alternatively, referring to FIG. 26,nanoparticles having a first size range 2502 (such as, for example,about 100 nanometers) can be applied to substrate 2402 and thennanoparticles having a second size range 2504 (such as, for example,about 5 nanometers) can be applied on top of the nanoparticles havingthe first size range 2502.

As shown in FIGS. 25 and 26, nanoparticles 2502, 2504 can be differentshapes. Although spherical nanoparticles 2502 and elongatednanoparticles 2504 are shown, those skilled in the art will recognizethat the nanoparticles can be other shapes, such as, for example,irregularly shaped, nanotubular, or other shapes.

FIG. 27 shows nanoparticles of differing size ranges being applied todifferent locations on substrate 2402. Nanofeatures 2702 at a firstlocation 2704 have a first size range and nanofeatures 2706 at a secondlocation 2708 have a second size range, different from the first sizerange. Optionally, as shown in FIG. 27, nanofeatures 2702 at firstlocation 2704 have a first shape, and nanofeatures 2706 at secondlocation 2708 have a second shape, different from the first shape.

The features shown in FIG. 27 can be formed by masking second location2708 of substrate 2402 with a mask so that nanofeatures cannot beapplied to second location 2708. Nanofeatures 2702 are then applied tothe exposed (first location 2704) portion of substrate 2402.

Then, the mask is removed from second location 2708 and a second mask isapplied over first location 2704 and nanofeatures 2706 are then appliedto the exposed (second location 2708) portion of substrate 2402.

The material used for the mask can be bees wax, fish glue, coconut oil,sequential dipping, tape, plastic caps, metallic feature, or any othermaterial or method can be used to cover substrate 2402. Alternatively,if the nanotexturing is applied by electrochemical deposition, only theportion of substrate 2402 to which the nanofeatures are to be applied isdipped in a chemical bath so that only that part of substrate 2402 iscoated.

Additionally, nanoparticles having different size ranges can be providedat surface 2404 to perform different functions. For example, a firstparticle size range is sized to enhance osteoconductivity and a secondparticle size range is sized to enhance anti-bacterial properties.

By way of example only, and referring back to FIG. 27, a texture extendsover at least part of the exposed surface 2404. The texture comprises aplurality of nanofeatures, such as, for example, differing sizes anddiffering shapes, as described above. The nanofeatures inhibit bacterialgrowth on surface 2404 and can have a size range between about 0.01nanometers and about 1,000 nanometers.

In an exemplary embodiment, a first range within the size range producesa first property and a second range within the size range produces asecond property, different from the first property. For example, thefirst property can inhibit bacterial adhesion on the surface 2404 whilethe second property enhances osteointegration of the texture 2406.Further, the first size range can be between about 0.01 nanometers andabout 1,000 nanometers, while the second size range can be between about15 nanometers and about 3 millimeters.

Referring to FIG. 28, a substrate 2802 has an exposed surface 2804 andhas a texture 2806 over at least part of exposed surface 2804. Texture2806 has a plurality of nanofeatures applied thereto. Texture 2806 has afirst particle size 2810 at a first location 2812, a second particlesize 2814 at a second location 2816, and a gradient 2818 of particlesize from first particle size 2810 to second particle size 2814 betweenfirst location 2812 and second location 2816.

FIG. 29 shows a graph of anti-bacterial properties of different sizednanofeatures and how they kill S. aureus bacteria. As seen on the graph,smaller sized nanofeatures (in the range of about 15 nanometers andsmaller) are more effective at killing S. aureus than larger sizenanofeatures (in the range of greater than about 30 nanometers).

By comparison, FIG. 30 shows a graph of osteointegration of nanofeatureson a substrate after 3 days (left column of each pair) and 5 days (rightcolumn of each pair). As can be seen, nanofeatures in the 30 nanometerrange demonstrate the largest amount of osteoblasts, indicating betterosteointegration capability.

Therefore, by providing nanfeatures of differing size ranges, such asabout 15 nanometers and smaller and about 30 nanometers, a nanotexturedsurface has both antimicrobial and osteo integration properties.

It will be further understood that various changes in the details,materials, and arrangements of the parts which have been described andillustrated in order to explain the nature of this invention may be madeby those skilled in the art without departing from the scope of theinvention as expressed in the following claims.

What is claimed is:
 1. A method for correcting spinal scoliosis in apatient, the method comprising the steps of: (a) providing anon-adjustable wedge having a generally planar posterior surface and agenerally planar lateral surface adjacent to each other, the posteriorsurface tapering from larger to smaller in a lateral direction and thelateral surface tapering from larger to smaller in an anterior-posteriordirection, forming a planar top surface extending obliquely to both theposterior surface and the lateral surface; and (b) implanting the wedgeinto a vertebra in a spine, thereby simultaneously correcting a spinalcolumn that has abnormal curvature into a lateral-to-medial direction aswell as in a posterior-to-anterior direction.
 2. The method according toclaim 1, wherein step (b) is performed by inserting the wedge into thevertebra in a lateral-to-medial direction.
 3. The method according toclaim 2, further comprising, prior to step (b), the step of performingan osteotomy on the vertebra by making an incision in the vertebra. 4.The method according to claim 3, wherein the insertion is made from alateral side of the vertebra inwardly toward the center of the vertebra.5. The method according to claim 3, wherein the incision is made to acontralateral side of the vertebra, with the implant being insertedtherein.
 6. The method according to claim 1, wherein step (b) results inpivoting a cranial plane of the vertebra relative to a caudal plane ofthe vertebra to make the cranial plane and the caudal plane closer tomatch a crainocaudal axis of the spine and aligned in a sagittal plane.7. The method according to claim 1, further comprising the step of: (c)securing the wedge in the vertebra with a retaining plate.
 8. A methodfor correcting spinal scoliosis in a patient, the method comprising thesteps of: (a) providing a non-adjustable wedge having: a first generallyplanar side surface; a second generally planar side surface adjacent tothe first generally planar side surface, the first generally planar sidesurface tapering from larger size to a smaller size in a directiontoward the second generally planar side surface and the second generallyplanar side surface tapering from a larger size to a smaller size in adirection away from the first generally planar side surface, the smallersize of the first generally planar side surface being adjacent to thelarger size of the second generally planar side surface; and a planartop surface extending in a plane oblique to the first generally planarside surface and also oblique to the second generally planar sidesurface; and (b) implanting the wedge into a vertebra in a spine.